1. Field of the Invention
The present invention is related to a method and system in the science of three-dimensional surface anthropometry and its application to product design.
2. Description of the Related Prior Art
Anthropometry is the study and measurement of human form. Traditionally, anthropometry has involved the manual location of landmarks on the human form, measuring one-dimensional distances between landmarks, and analyzing those measurements with statistical methods.
Anthropometry has practical applications in the design of work environments and in the custom-fitting of products to the human body, for example, by referring to lists of measurements, such as the length of an arm or the width of the head. Such information is usually available for various percentiles, allowing it to be used to design a product that may accommodate some definable portion of the population. These methods are useful, but are inadequate for products that need to fit to conform to surface contours of the body.
For many years, product designers have used whatever anthropometrical data was available to them to design products to fit users. Sometimes this has involved using poseable human figures, both large and small, in drawings of products, to verify reach, lines of site, etc. Designers also refer to anthropometric data to ensure that handles will fit users' hands, that helmets will fit the largest and smallest sample heads, etc. When designing products like respirators that are required to seal against a user's face, designers are often forced into a trial and error process to devise contours that will fit their intended population of users.
One design method that has been employed involves using a model head or mannequin that is somehow representative of users. This might be a so-called “average head” such as the Alderson head model. Designing is this way may be problematic for many reasons, but especially because it does not account for the extremes in size variations of a population.
Designers may also attempt to find representative users with more extreme proportions, but it may be difficult to anticipate what features may become limiting or otherwise significant when the relationship between the product and wearer is complex. In most cases products are optimized to fit a very small sample of users and then tested to demonstrate that for most other users they fit “well enough.” Often deficiencies in fit are not realized until far into the development process, when rigorous fit testing can be done using prototypes on large numbers of subjects.
Many products are intended for use in countries other than those in which they were designed, making it even more difficult to identify fit problems early in the process. In addition, in some countries where products are designed for the country's populace, the demographics of the population are changing quickly enough that products that used to fit their intended users no longer do.
Today, most products are designed using 3D computer software. Computer Aided Design, or CAD, software represents the three-dimensional forms of parts and their interrelationships in great detail. Three-dimensional databases of measurements can be used to analyze the structural and mechanical properties of a product and may also be used to make realistic working models of the product. Further down the line in the process, the CAD representations may be used in the manufacture of the product itself.
Efforts have been made to incorporate three-dimensional scanning and computers into the design process. These efforts may generally be referred to as Three Dimensional Surface Anthropometry, in which laser scanners are used to generate accurate three-dimensional surface models of people of various shapes and sizes.
When 3D laser scanning machines became available in the 1980s, a number of researchers began scanning the human form and attempting to use the data to fit products to intended users. Most of these efforts were focused on the human head, and the applications were mostly for military products. Typically, these efforts involved comparing product geometry to numerous scanned individuals, which is basically the digital equivalent of fitting the product to many individual test subjects, or to having a colleague from “down the hall” try on your prototype. Product design in this manner is a very time consuming process if done right, and, more often than not, relies on only a limited set of individuals being tested.
In the late 1990s a large number of subjects from the United States and Europe were scanned as part of an effort known as the Civilian American and European Surface Anthropometry Resource, or CAESAR project. The project was funded by large corporations hoping to use the data to develop products that fit users better. The CAESAR project, however, focused on data collection and not manipulation or product design.
It would be desirable to create a method and system that overcome one or more shortcomings in the prior art and take advantage of the potential benefits presented by digital anthropometric scanning.